Marco's new code for evaluating two unstoppable passed pawns where
one pawn promotes a single ply before the other tried to detect
cases where the pawn that promotes first could immediately capture
the pawn that promotes a ply later, but didn't work in cases where
the two pawns are on the same file. An example of this is the
following position:
8/8/3K4/2P5/2p5/3k4/8/8 w - -
With the new code, such positions are handled correctly.
Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8));
Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8));
Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8));
Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8));
- Bitboard b = pos.attacks_from<QUEEN>(winnerQSq);
+ Bitboard b = pos.occupied_squares();
+ clear_bit(&b, pawnToGo[winnerSide]);
+ clear_bit(&b, pawnToGo[loserSide]);
+ b = queen_attacks_bb(winnerQSq, b);
if ( (b & pos.pieces(KING, loserSide))
||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq)))
if ( (b & pos.pieces(KING, loserSide))
||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq)))